An exhaust gas aftertreatment system of a vehicle may include a differential pressure sensor to sense the exhaust pressure within the treatment system. The differential pressure sensor sends a signal to a control module, which uses the signal for various calculations and/or to determine initiation of certain events, such as but not limited to regeneration of a Diesel Particulate Filter (DPF).
Vehicles will often include On-Board Diagnostic (OBD) algorithms to determine if various components are functioning properly, or may be malfunctioning. For example, vehicles may include an OBD algorithm to determine if the DPF is functioning properly, or is malfunctioning. The OBD algorithm for the DPF uses the signal from the differential pressure sensor in the exhaust gas aftertreatment system, along with other inputs, to determine if the DPF is functioning properly or is malfunctioning. As such, a malfunction in the differential pressure sensor may cause an incorrect assessment of the DPF's functionality.
Vehicles may further include an OBD algorithm to determine if the differential pressure sensor is functioning properly, or is malfunctioning. However, it is possible that the differential pressure sensor may be malfunctioning, for example providing erratic pressure signals that are otherwise within an allowable range of pressure signals, yet not fail the OBD algorithm for the differential pressure sensor. Such an occurrence, when the OBD algorithm passes a differential pressure sensor that is providing erratic pressure signals, may cause an incorrect assessment of the DPF diagnostic algorithm, which may cause unnecessary replacement of the more expensive DPF instead of the less costly differential pressure sensor, or failure to detect a faulty DPF.